Abstract: A system for aligning a drilling module on a jack-up rig with a drilling module support surface on a fixed rig wherein the angular disposition of the drilling module is varied by moving a portion of the jack-up rig on at least one of the legs of the jack-up rig to bring the angular disposition of the drilling module into alignment with the angular disposition of the drilling module support surface on the fixed rig prior to transferring the drilling module from the jack-up rig to the fixed rig. The system also includes a position assembly for positioning the drilling module on the drilling module support surface in a predetermined aligned position.

Abstract: A device for supporting a turntable (1) on a vessel, especially a vessel for use in connection with drilling for and production of oil, which vessel is anchored to the sea floor, via the turntable (1). The turntable (1) comprises a horizontal circular flange portion (2) and a cylindrical portion (3) extending coaxially relative to the latter and downwards from the flange portion (2) into a vertical through hole (7) in the hull (6). Said device comprises bearing means (21, 22, 23, 24) which are connected with the vessel's hull (6) and comprise one or a plurality of bearing members (31, 34, 41, 46) adapted to bear against the respective bearing faces (11, 12, 13, 14) of the turntable flange portion (2). The bearing means permit relative rotation of the turntable (1) and the hull (6) about a substantially vertical axis. According to the invention first and second bearing means (21 and 22, respectively) are provided beneath the peripheral portion of the turntable flange and are designed to support turntable (1).

Abstract: A jack-up rig includes a cantilever beam assembly and a drilling module is mounted on the cantilever beam assembly. The jack-up rig also includes means for moving the cantilever beam assembly from the storage position to extended positions wherein a rearward end of the cantilever beam assembly is extended from the jack-up rig. The fixed platform comprises a fixed platform support structure having a drilling module support surface and a beam opening. The jack-up rig is positioned near the fixed platform with the cantilever beam assembly generally aligned with the beam opening in the fixed platform support structure. The cantilever beam assembly then is extended through a portion of the beam opening to an extended position wherein the drilling module is supported on the cantilever beam assembly a distance generally above the drilling module support surface. The jack-up rig then is lowered to a position wherein the drilling module is supported on the fixed platform support structure.

Abstract: Method and apparatus for transferring a derrick from a jack-up rig to an offshore platform are disclosed which include positioning the rig and platform next to each other, providing an elevator pad on the platform that is set at the same level as the deck of the rig, installing skid beams between the deck of the rig and the top of the elevator pad, skidding the rig from the rig to the pad, and lowering the pad and derrick to the normal level of the platform for use in drilling operations.

Abstract: A jack-up rig includes a cantilever beam assembly and a drilling module is mounted on the cantilever beam assembly. The jack-up rig also includes means for moving the cantilever beam assembly from the storage position to extended positions wherein a rearward end of the cantilever beam assembly is extended from the jack-up rig. The fixed platform comprises a fixed platform support structure having a drilling module support surface and a beam opening. The jack-up rig is positioned near the fixed platform with the cantilever beam assembly generally aligned with the beam opening in the fixed platform support structure. The cantilever beam assembly then is extended through a portion of the beam opening to an extended position wherein the drilling module is supported on the cantilever beam assembly a distance generally above the drilling module support surface. The jack-up rig then is lowered to a position wherein the drilling module is supported on the fixed platform support structure.

Abstract: A mobile marine drilling assembly has a horizontally disposed pontoon which floats on or is submerged below the surface of a marine environment. A first vertically disposed column is secured to the pontoon and extends upwardly therefrom. A work platform has an opening through which the column extends, and the platform overlies the pontoon and is vertically movable relative thereto along the column. A jack system is operably connected with the work platform and with the column for jacking the work platform along the column between a first position wherein the pontoon floats on the surface of the marine environment and a second position wherein the pontoon is disposed a substantial distance below the surface of the marine environment. An anchor is secured to the floor of the marine environment.

Abstract: A production platform for offshore exploitation of hydrocarbons comprises a truss tower (1) which rests on the sea floor (2) and supports a deck structure (3) provided with a drilling module (5). In order to obtain optimum mutual distance between production pipes (10) at the deck level, the skid beams (6) of the drilling module are arranged parallel to a diagonal (9) in the cross-section of the truss tower. Weight savings in the truss tower (1) may be obtained by arranging the deck structure (3) with its sides parallel to the diagonals (9) of the truss tower (1).

Abstract: A cantilevered drilling structure including a base unit having a side positionable generally adjacent a well head, and a drilling rig mast assembly positioned generally above and supported by the base unit. The base unit has a cantilever member extending out from its side, spaced from the ground, and having an outer portion spaced from the side. A telescoping leg extends down from the outer portion and is spaced from the side such that the side and the leg are positionable on opposite sides of a well head. The telescoping leg is movable between a lower support position and a higher raised position high enough to pass over flow lines when the drilling structure is moved along the well row. A skidding floor mechanism moves the drilling rig mast assembly along the base unit between a drilling position over the cantilever member when the telescoping leg has been extended and a moving position closer to the center of gravity of the base unit.

Abstract: A floating semisubmersible off-shore drilling platform or the like comprises an upper working level portion and a lower pontoon portion. When the platform is transported from one place to another, it floats on the pontoon portion, but when it is working as a stationary unit in open water, it is submerged deeper, so that the pontoon portion is at a considerable distance below the water surface and the working level portion is at a considerable distance above the water surface. The platform is adapted to withstand ice pressure from ice occurring in the ambient water by giving the pontoon portion of the platform a form particularly advantageous in ice conditions. When ice occurs, the platform is lifted to such a position, that its pontoon portion comes to float at the water surface level.

Abstract: A multi-well hydrocarbon development system is economically established and operated by drilling cluster wells through the piles securing the base structure which supports a semisubmersible tension leg buoy through a single leg assembly. The buoy includes a turntable with skid beams on which a drilling rig is slidably mounted so that the rig can be positioned over the piles and cluster wells can be drilled through the piles. Produced fluids are transported into a containment means for separation and storage within the buoy. A captive processing vessel may be moored to the buoy and a means is provided to dispose processed water and/or gas responsibly.

Abstract: An ice-breaking structure having a platform member adapted to be flexibly connected to an off-shore fixed well shaft in a manner which allows the platform to lift and/or tilt relative to the shaft is disclosed. The platform member has at least one lower surface which slopes upwardly toward an outer edge thereof and is adapted to be positioned on the shaft so that the sloping surface extends both above and below sea level. As oncoming ice approaches and contacts the structure, the sloping surface lifts a portion of the platform upwardly onto the ice so that part of the weight of the platform is carried by the ice. This weight on the ice aids in breaking-up the same. Various embodiments of the general concept are disclosed.

Abstract: A marine pipeline surveying apparatus useful for locating buried pipelines includes a barge having a work deck with a dolly mounted on the work deck for movement on the deck upon a provided track. A slot in the barge can be provided so that workers can move completely around the dolly. The dolly provides a gimbal type articulating support for supporting a hollow casing during operation. The gimbal support allows the articulating movement to compensate wave action on the barge so that the wave action is not transmitted to the casing. During operation a magnetometer placed in the casing bore can be used to "roughly" position the barge and casing above the pipeline to be located. Then the barge can be anchored in position over the pipeline as dictated by the magnetometer "rough" positioning. The magnetometer is then removed from the casing bore and the casing provides a guide for a probe rod such as a jet probe which is placed within the casing.

Abstract: Disclosed is a cantilever mobile marine rig with hydraulic load equalizer. The rig includes a deck structure and a cantilever assembly slidingly mounted on the deck structure. The hydraulic load equalizer includes a plurality of hydraulic cylinder and piston assemblies positioned between the deck structure and the cantilever assemblies. The hydraulic cylinder and piston assemblies each have substantially the same effective area and are interconnected so as to allow substantially free and unimpeded flow of hydraulic fluid among the cylinder and piston assemblies.

Abstract: The universal joint construction for use at the bottom of a connection between a surface platform and a foundation anchored on the bottom of the sea comprises an outer top ball cup which is adapted to be connected up to the platform and an inner bottom ball cup disposed within the outer top ball cup enclosing the bottom thereof. The inner ball cup has an exterior in slidable engagement with the interior of the outer ball cup and a bell forming an enclosed pressure space is defined between the exterior of the upper cup and the bottom cup. In addition a ring seal bearing is defined between the inner bottom ball cup and the outer top ball cup adjacent the edge of the outer top ball cup. The interior of the bottom ball cup carries a plurality of shoes which bear in sliding engagement with the interior of the top ball cup.

Abstract: A support structure (20) for supporting the freestanding portion of a mudline suspension wellhead includes first and second support arms (56) attached to and extending from an offshore drilling platform (24). The structure is aligned below a cantilevered type drilling derrick (40). A gantry (60) is supported by and slidable relative to these arms. A cradle structure (66) is mounted for lateral movement on the gantry. Structure is provided for positioning the gantry along the longitudinal length of the arms and for positioning the cradle along the longitudinal length of the gantry. Movement of the cradle structure relative to the gantry and of the gantry relative to the support arms defines a zone between the support arms and between the drilling platform and the outermost point of travel of the gantry in which the cradle may be selectively positioned. The gantry and cradle are aligned relative to the wellhead, and structure (290, 320) associated with the cradle is provided for clamping the wellhead thereto.

Abstract: A support arrangement for a platform held in suspension from an offshore frame structure which provides damping between the structures in inverse proportion to the magnitude of a seismic shock. The effects of seismic shocks on the suspended platform are mitigated by providing first and second nonlinear shock absorbers coupled laterally in first and second horizontal directions between the platform and the frame structures. The first and second shock absorbers are designed to be substantially rigid to provide stiff damping for relatively low amplitude seismic forces while providing substantially softer or less rigid damping for relatively high amplitude seismic forces, such that the suspended load is able to move relatively freely in all horizontal directions when it is subjected to relatively severe seismic shocks.

Abstract: A working platform for oil drilling operations in ice covered sea areas, which essentially comprises oil drillig equipment, an oil drilling pipe connecting the oil drilling equipment to the sea bottom, and a floating frame having a buoyancy and a strength enough to stand the pressure of an ice covering and being movable in accordance with movement of ice covering; the floating frame is disposed surrounding such a surface area of the ice covered sea as lying around the oil drilling pipe, whereby the pipe is protected by the floating frame against action of the pressure of ice covering during oil drilling operations.

Abstract: A walking platform construction comprises a barge or work platform and a plurality of legs movable in a vertical direction and securable with respect to the barge or platform. The barge or platform has a plurality of independently movable auxiliary frames each comprising one or two legs movable and securable in vertical direction with respect to the auxiliary frame. Each auxiliary frame is disposed in a rectangular recess of the barge or platform and movable within the recess in the longitudinal direction of the recess as well as in a transverse direction. In the case in which the auxiliary frame is a long rectangular frame having two legs, each end of the frame has means to move this end in a transverse direction to the frame's longitudinal axis.

Abstract: An auxiliary offshore rig adapted to be used for relieving the primary offshore rig on an offshore platform of well activities relating to tubular member or cable operations. The auxiliary offshore rig includes in one embodiment a truss member mounted for movement along the platform, a racking tower for receiving tubular members therein mounted on the truss member, and a working cage mounted within the racking tower and supported by the truss member adapted to be positioned in alignment with the well for providing a secondary working area beneath the rig floor which is mounted atop the racking tower.

Abstract: Disclosed is an improved fixed offshore platform and method of erecting the same. The platform has an open truss structure with upper and lower deck levels. The upper deck has removable floor sections to allow installation of equipment down through the truss structure. The platform is provided with pads for mounting equipment and housing in modules on the deck. No flotation is provided in the platform and means are provided for supporting the platform on the deck of a simple barge. The platform is generally triangular in shape having three caisson legs with one leg enlarged to allow drilling therethrough. Jacks are provided for gripping the legs and a crane is mounted on the deck to move along tracks provided thereon. In erecting the platform, the platform is first barged to the location of installation on a simple barge with the legs in a vertically-extending position and the platform in its normal operating position with the crane thereon. The barge is moored in position over a well site.

Abstract: An upper deck structure which contains the equipment necessary for operation of an oil rig is positioned on top of the main deck of the rig, the main deck being supported by vertical pilings or columns. The upper deck is not rigidly connected to the main deck but is held in place by frictional engagement therebetween. Such engagement can be enhanced by the placement of a rubber layer between the two decks. The oil rig is consequently made much lighter in weight and is easier to put together.